Tuesday, April 05, 2022
Covid-19 first-of-its-kind study saw volunteers infected for science
The first “controlled investigation” of Covid-19 has been carried out and it has allowed researchers to dispel a widespread myth about the way people become infected.
The human challenge study involved people being deliberately infected with a virus — in this case it was SARS-CoV-2, the virus that causes Covid-19.
The study, published last week in the journal Nature Medicine, found that only the most minuscule amount of the virus is needed to infect a person — as much as a single airborne droplet from a person sneezing, coughing or talking.
It also found that, despite what most people have been told, viral shedding and transmissibility occur at high levels when a person is infected regardless of whether they have severe or mild symptoms.
Researchers from University College London Hospital, Imperial College London and the University of Oxford, among others, were also able to bust another myth, one pushed mostly by anti-maskers.
They found the virus is “present at significantly higher (levels) in the nose than the throat”, a finding they said provides “clear evidence that emphasises the critical importance of wearing face coverings over the nose as well as the mouth”.
“Deliberate human infection of low-risk volunteers enables the exact longitudinal measurement of viral kinetics, immunological responses, transmission dynamics and duration of infectious shedding after a fixed dose of a well-characterised virus,” authors wrote.
“Experimental challenge with human pathogens requires careful ethical scrutiny and regulation but can deliver unparalleled information that may inform clinical policy and refinement of infection control measures.”
Those “unparalleled findings” were made possible thanks to 36 volunteers aged between 18-30 years.
The participants were each given a dose of the virus via a small tube into their nose, then housed in a high-containment quarantine unit at the Royal Free London NHS Foundation Trust with 24-hour close medical monitoring and full access to clinical care.
Researchers found that 18 participants — equating to 53 per cent — became infected with a viral load “rising steeply and peaking five days after inoculation”.
They said the virus was “first detected in the throat but rose to significantly higher levels in the nose”.
“Viable virus was recoverable from the nose up to 10 days after inoculation, on average.”
The researchers found that most of those who became infected recovered quickly. There were no serious adverse events and “mild-to-moderate symptoms were reported by 16 (of the 18) infected participants”.
The other two who were infected remained asymptomatic.
The researchers also looked at how Covid-19 impacts a person’s sense of smell.
They used smell identification tests with help from the University of Pennsylvania and found that 15 of the 18 participants who were infected reported “some degree of smell disturbance”.
Nine participants experienced complete smell loss, known as anosmia, but researchers said they “improved noticeably before day 28”.
Six months after the study ended, one of the participants has still not regained their full smell.
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Moderna COVID-19 Vaccine Trial Results Not Strong Enough to Warrant Authorization for Children: Experts
Regulators in the United States and elsewhere should not clear Moderna’s COVID-19 vaccine for children based on a clinical trial that found the shot under 50 percent effective in preventing infection, experts say.
Moderna is pushing for emergency authorization from the U.S. Food and Drug Administration (FDA) for its jab for kids as young as 6 months of age, based on the results of the trial.
The decision to authorize would mean some 20 million of the youngest children in America could get a COVID-19 vaccine for the first time since the pandemic started.
Some parents and experts want that to happen sooner rather than later and are willing to accept less than ideal results. But others aren’t convinced that most of the age group needs a vaccine, especially a shot that doesn’t perform well against emerging variants.
While some children have died or gotten seriously ill from COVID-19, the disease caused by SARS-CoV-2 virus, their vulnerability is much smaller compared with older people, and most youth experience mild or no symptoms, according to the Centers for Disease Control and Prevention (CDC).
A recently published study found T-cells, a form of protection, worked better against the virus in infant mice than in adult mice; while another concluded infants and toddlers who contract the virus have a superior immune response when compared to adults.
The very low risk of severe COVID-19 for children presents a much different risk-benefit calculus, experts say.
Particularly for children, “you’ve really got to show the benefits markedly outweigh any risks,” Dr. Peter Collignon, an infectious diseases physician at Canberra Hospital, told The Epoch Times over Zoom.
In 5- to 11-year-olds, for instance, a British government panel determined that 2 million vaccine doses would prevent as few as 17 hospitalizations due to acute COVID-19. Amid a less severe future variant, some 4 million doses would be needed to prevent a single intensive care unit admission.
“No prospective clinical or epidemiological data that I am aware of has been provided to show that younger age groups [tested] in the Moderna study would fare any differently,” Dr. David Gortler, an FDA policy oversight fellow at the Ethics and Public Policy Center who used to work for the FDA, told The Epoch Times in an email.
Does the Trial Meet Regulatory Standards?
The trial from which Moderna announced interim results is called KidCOVE. It involves two groups: children 6 months of age to under 2 years, and children 2 years of age to 5 years.
The U.S.-based company, on March 23, released a summary of interim data, announcing the trial met its endpoint, which was a certain threshold of neutralizing antibody response in both age groups after receiving a two-dose series of the vaccine.
The results were so positive that “we are working with the U.S. FDA and regulators globally to submit these data as soon as possible,” Stephane Bancel, Moderna’s CEO, said in a statement.
But the actual clinical impact was substandard.
During the wave driven by the Omicron virus variant, the vaccine was just 43.7 percent effective in the youngest group, and 37.5 percent effective in the other children.
Both measures are lower than the 50 percent bars established by the FDA and the World Health Organization for emergency authorization.
“That’s not acceptable by the FDA’s own standards,” Dr. Steven Hatfill, a virologist who advised the Trump administration, told The Epoch Times.
“Our approach has always been to conduct a regulatory review that’s responsive to the urgent public health needs created by the pandemic, while adhering to our rigorous standards for safety and effectiveness. While we cannot comment on any submissions pending before the agency, we remain committed to conducting a timely and thorough evaluation of the available data and information on the use of COVID-19 vaccines in the youngest children,” Alison Hunt, an FDA spokeswoman, told The Epoch Times in an email.
Moderna did not respond to requests for comment.
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Long Covid a serious problem
By the end of the year, modelling suggests tens of thousands of Australians will have experienced lingering symptoms of the virus.
Health economist Professor Martin Hensher warns that long COVID poses a serious public health threat and critical data is missing.
“At the moment we really have no idea of the extent of long COVID in Australia,” he said. “We are flying pretty blind.
Professor Hensher, who worked alongside a team modelling long COVID at Deakin University, estimates that at 12 weeks post infection, anywhere between 80,000 and 325,000 of the more than two million Australians infected during the first Omicron wave alone will have ongoing symptoms.
And, while a large proportion are predicted to recover within six months, thousands are expected to experience persistent symptoms.
He is part of a growing chorus of experts calling for the urgent rollout of a national survey to measure the scale of long COVID in Australia and a database to track symptoms.
In Australia, up to 30 per cent of seriously ill COVID-19 patients have reported at least one symptom persisting after six months. The most common symptom was shortness of breath, but others included fatigue, headaches and a loss of taste or smell.
Ms Costello, who was double vaccinated six months before contracting the virus, and before boosters were approved, is one of an estimated more than 90,000 Australians who have a smell or taste disorder after six months.
The figure in Australia is far below other parts of the world where Delta was the prevalent variant.
Studies have found up to 60 per cent of people who had Delta lost their sense of smell and/or taste, compared to one in five with Omicron, the most common variant in Australia. About two per cent of those people will have impaired senses long term.
People’s experiences range from complete or partial loss to distorted and imagined senses. Some people complain certain foods taste like garbage or rotting meat, while others can smell faeces or smoke when neither are nearby. Ms Costello often gets phantom garbage smells.
Exactly why this occurs is still unknown, but there is an emerging consensus, including by a team studying the phenomena at Harvard Medical School, that smell loss occurs when the coronavirus infects cells that support neurons in the nose.
To the frustration of sufferers, there is no easy cure for olfactory dysfunction.
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Also see my other blogs. Main ones below:
http://edwatch.blogspot.com (EDUCATION WATCH)
http://antigreen.blogspot.com (GREENIE WATCH)
http://pcwatch.blogspot.com (POLITICAL CORRECTNESS WATCH)
http://australian-politics.blogspot.com/ (AUSTRALIAN POLITICS)
http://snorphty.blogspot.com/ (TONGUE-TIED)
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